Speed modulating device



May 6, 1941.

L. JONES SPEED MODULATING .DEVICE /vo z a Filed March 22, 1938 PatentedMay 6, 1941 p UNiTED STATES PATENT FFICE SPEED MODULATING DEVICE LewisJones, Youngstown, Ohio Application March 22, y1938, Serial No. 197,480

5 Claims.

This invention relates to speed modulating devices for motor vehicleengines, and more particularly to an automatic device for admittingsupplemental air into the intake manifold of a motor vehicle engineprimarily to tend to maintain a uniform vehicle speed and incidentallyto effect a saving in fuel costs.

I am aware that numerous types of auxiliary air inlet valves for motorvehicle engines have been developed principally for the purpose ofeffecting a saving in fuel costs. These valves have been of severaltypes and, so far as I am aware, all possess inherent disadvantageswhich more than outweigh their advantages. For example, valves of thetype referred to of which I am aware possess the disadvantage ofrendering the fuel mixture too lean under substantial load conditions onthe vehicle engine, thus materially reducing the engine power whenneeded. Moreover, such devices are inherently disadvantageous inpractice for the reason that they tend to result in too high a vehicleidling speed, thus requiring frequent disengagement of the clutch of thevehicle when moving in slow traffic.

'I'he present device has for its principal object the provision of anovel control mechanism which tends to render uniform the speed oftravel of a motor vehicle for a given throttle opening and under varyingload conditions.

More specifically, an object of -the invention is to provide a valvemechanism which functions automatically, at any given throttle opening,to admit supplemental air into the intake manifoid when the vehicle istraveling under light load conditions, as when going down hill, andwhich functions to completely cut off the admission of auxiliary airduring increased load conditions, as when the vehicle is travelingup-hill,

thus resulting in a marked tendency for the veidling speeds andeliminating the necessity for 4 frequently disengaging the clutch of thevehicle v when traveling in slow traiiic.

A further object is to provide an auxiliary air valve of the characterreferred to which functions at the relatively high vacuum present whenthe vehicle engine is idling to cut off the admission of auxiliary airinto the intake manifold, and which automatically functions to admitauxiliary air under varying vacuum conditionsin the intake manifoldbetween the relatively high idling vacuum and a substantially lowerpredetermined vacuum below which the vehicle engine demands maximumexplosive efficiency incident to increased load conditions.

A further object is to provide a valve mechanism of the characterreferred to which functions to cut off the admission of supplemental airat intake manifold vacuum conditions which are present at normal idlingspeeds, but which functions to admit supplemental air above and belowsuch vacuum conditions.

A further object is to provide a valve mechanism which possesses theinherent desirable characteristics referred to and which incidentallyincreases fuel mileage and thus reduces fuel costs.

Other objects and advantages of the invention will become apparentduring the course of the following description.

In the drawing I have shown two embodiments of the invention. In thisshowing- Figure 1 is a side elevation of a motor vehicle carburetor andintake manifold showing a part of the vehicle engine, the manifold beingbroken away,

Figure 2 is an enlarged axial sectional view through the valvemechanism,

Figure 3 is a sectional view on line 3-3 of Figure 2, and,

Figure 4 is a View similar to Figure 2 showing a modified form of theinvention.

Referring to Figure 1, the numeral l0 desigiates a portion of a motorvehicle engine having a conventional intake manifold II for supplying acombustible fuel mixture to the several cylinders of the engine. Suchfuel is provided through the normal functioning of the usual carburetorI2 in the riser I3 of which is arranged a conventional throttle Ii.While the arrangement shown is conventional for a down-draft carburetorof the type now in common use, it will become apparent that the presentinvention is not limited in its use to any particular forms ofcarburetor or intake manifold.

Referring to Figures 1 and 2, the present invention comprises apreferably conical valve body I5 having a cylindrical upper end I 6which is externally threaded for reception in the flange of a cap I1.This cap is provided with an axial threaded portion I8 to be received ina tapped opening I9 formed in the bottom of the intake manifold IIpreferably in axial alignment with the riser I3. The cap I'I is furtherprovided with an axial tubular portion 20 formed integral with thethreaded portion I3 and of somewhat smaller diameter than the latter tofacilitate its introduction through the opening I9. The upper end of thetubular member 26 terminates in close proximity to the throttle valve I4for a purpose to be described.

It will be noted that the opening 2I through the tubular member! 26communicates at its lower end with the interior of the valve body I5 toreceive air therefrom. Such air is admitted into the valve body I5,under conditions to be referred to, through a lower axial opening 22formed in a threaded extension 23. This extension may have a pipe 24(Figure 1) leading to the crank case of the motor vehicle or directlycommunicating with the atmosphere through a suitable air cleaner.However, the particular source of air supply forms no part of thepresent invention and need not be illustrated in detail'. The interiorof the valve body is provided around the upper end of the opening 22with a valve seat 25. arranged within` the valve body I5, the' valveelement 26 preferably being conical and corresponding in taper to thetaper of the valve body I 5. The lower end of the valve element' 26forms a valve 21 adapted toi engage the seat 25, and within the valveface' 21. the lower end of the valve element 26 is preferably provided'with a recess 28 for a purpose Vto be described. In order to assist inthe' proper operation of the device in the manner to be referred. to,the valve element 26 is preferably provided with a plurality of annular'recesses 29 formed in itsv outer face.

A compression: spring 30 has its lower end engaging the inner face ofthe bottom of the valve element 26,- the diameter of the springpreferably equalling the diameter of the face of the valve element 26which it engages. The upper end of the' spring fits around a dependingcylindrical member 3I preferably formed integral with the cap I1. Themounting of the spring tends to minimize lateral movement of the Valveelement 26 when the latter is in its open orY intermediate position. Thespring 36 is loaded to a predetermined extent to be referred to laterand the spring tension may be adjusted by turning the cap I1 upwardlyand downwardly on the upper end I 6 of the valve body. A jam nut 32 isprovided for securing the cap vI1 in any desired position in accordancewith the desired loading of the spring 30.

The upper end 33 of the valve element 25 also acts as a valve and isengageable with a valve. seat 34 formed on the lower face of the cap I1.Under predetermined relatively low vacuum conditions in the intakemanifold the valve 21 engages the seat 25, and under higher vacuumconditions, for example at idling speeds of the vehicle engine, thevalve 33 engages the seat 34. Under intermediate vacuum conditions, thevalve element 26 occupies variable intermediateA positions between thetwo' positions referred tofor the admission of supplemental air into theintake manifold, as will be described in detail later.

The form of theinvention shown in Figure 4 comprises parts substantiallyidentical inv structure and function to the form shown in Figure 2 andincludes other structural features to perform additional functions. Thevalve body, cap and spring in Figure 4 may be identical with thecorresponding parts previously described and have been indicated by thesame reference numerals. In place of the valve element 26, the form ofthe invention shown in Figure 4 is provided with a somewhat similarconical valve A ioating valve element 26 is* I lit tension' of thespring 3U.

element 35 having a valve 36 at its lower end engageable with the seat25 and a. Valve 31 at its upper end engageable with the seat 34. Insteadof the recess 28, the valve element 35 is provided in its lower end withan axial opening 38 therethrough and the interior of the valve element35 is provided with a valve seat 39 engageable by a poppet valve d6.This valve may be provided with an upstanding cylindrical flange 4I forreception in the lower end of the spring 30.

The operation of the form of the invention shown in Figures 1, 2 and 3is as follows: Y It will be apparent that the valve element 26 functionsas a pressure responsive member and its movements and positions willdepend upon differential pressures existing above and below suchelement. When a motor vehicle engine is idling, tests have indicatedthat there will be a vacuum of approximately 18 inches of mercurypresent in the intake manifold, this vacuum varying with differentengines as will be apparent. 1n theA present device, the tension of thespring 36 and its .relation totheV valve element 26 are so designed thatthe differential pressure affecting'` theI valve element 26 under thevacuum conditionsY present when the motor vehicle engine is idling willbe suincient to overcome the tension of the spring 36Y and thus move thevalveelement 26upwardly to engage the valve face 33 against the valveseat 3i. As previously stated, the tension of the spring is Vadjustablein accordance with the position of the cap I1 on the valve body and theproper tension is provided whereby the valve face will engage the seat3IIA at the partial vacuum existing under idling .engine conditions.Thus when the engine is idling, it will be apparent that air ispreventedfrom entering the intake manifold through the passage 2I.

Whileconditions in different engines will vary as is well known, in anaverage installation the designs of the parts including the spring 30are suchl that it requires an intake manifold vacuum of at least 13inches of mercury to move the valve member 26 to unseat the valve 21against the Under practically all load conditions there will be presentin the intake manifold` a vacuum of less than 10 inches of mercury, andunder such load conditions it will be apparent that the-valve 21.engages the seat 25 and thus prevents the admission of air into theintake manif old.

At intake manifold vacuums between approximately 10l inches andapproximately 18 inches the valve element 26l will occupy intermediatepositions with both of its valves 2l and 33 spaced from their respectiveseats, thus admitting air into the intake manifold, the air owingthrough the space between the outer surface of the valve element 26-andthe inner surface of the valve body I5. It will be apparent that dueto the conical shape of the parts referred to, the crosssectional areaVbetween the element 26 and valve body,'I5 will increase as the spring33 is progressively compressed, thus providing for the admissionv of airat progressively increasing rates until the valve 33 engages the seat34. The

,grooves 29 are provided to increase the surface friction of the airagainst the conical outer face of the valve element 26, thus increasingthe effectiveness of the' inilowi'ng air for maintaining the valve 21oif. its seat. The recess 26 also is provided to increase air frictionagainst the valve 26 forV the samefpurpose.

It will. be apparent that the vacuumy present in the' manifold whentheengine is idling is relatively high and the degree of vacuum is lowerthan the idling vacuum under most operating conditions. Thereforethevalve mechanism in Figure 2 is effective for admitting air under mostoperating conditions other thany idling conditions or when the vehi-cleengine is traveling under a substantial load. If the vehicle istraveling at high speed and under Va light load whereby a vacuum ofgreater than 18 inches of mercury will be present in the intakemanifold, the valve 33 will engage the seat 34 to cut off the admissionof air, and under such conditions the vehicle will function inaccordance with conventional operation without the admission `ofauxiliary air.

Assuming that the vehicle is traveling on a level highway with a vacuumin the intake manifold of 14 inches of mercury, for example, the valveelement 25 will occupy a position inter,- mediate its two limits ofmovement and auxiliary air will be admitted into the intake manifold. Ifthe vehicle now starts to ascend a slight grade and the operator doesnot change the position of the throttle, the increased load conditionson the engine for the given throttle opening will reduce the degree ofvacuum in the intake manifold and the valve 21 will move toward its seatto restrict the admission of supplemental air into the intake manifold.If the increased load is sufficient to reduce the manifold vacuum toapproximately l inches of mercury or less the valve 21 will engage itsseat 25 to completely cut oi the ad.- mission of supplemental air.

On the other hand, if it is assumed that the vehicle is traveling on alevel highway with a vacuum of approximately 14 inches of mercury in theintake manifold and the vehicle then starts to des-eend a grade, thedecreasing of the load on the engine in proportion to the throttleopening will increase the degree of vacuum and will move the valveelement26 upwardly to a greater extent. Under the grade ascendingconditions the cutting off of the auxiliary air will provide a richermixture for the engine to satisfy the demands for greater power, thustending to prevent the vehicle speed from being retarded. Under thegrade descending -conditions referred to, the admission of a greaterpercentage of air into the intake manifold will decrease the powerdeveloped by the engine and thus tend to decrease the speed.

As previously stated, the tubular member 20 preferably extends to apoint adjacent the carburetor throttle, thus providing a flow of airwhich is counter to the flow of the explosive mixture. This action notonly dilutes the explosive mixture but it also tends to retard the flowof the explosive mixture from the carburetor to the engine cylinderswhich is desirable under the conditions in which supplemental air isadmitted to the engine. The arrangement referred to possesses anadditional advantage in that the supply of air at the remotest possiblepoint from the engine cylinders with the counter-now referred to assuresa homogeneous mixing of the auxiliary air with the explosive mixturefrom the carburetor before the resulting mixture reaches the enginecylinders.

Aside from the functioning of the valve 4B and associated parts, theform of the invention shown in Figure 4 is identical with thatpreviously described, the valves 36 and 31 engaging their seats 25 and34 under the same conditions that the valves 21 and 33 in Figure 2engage the corresponding seats. Fon intake manifold vacuums up to 18inches of mercury, or the vacuum under idling engine conditions, thevalve 4@ remains on its seat 39 and moves as a unit with the element 35.

It will be apparent that the valve 31 engages the seat 34 under idlingengine conditions, atmospheric pressure acting on the lower faces of thevalve 40 and the lower and side surfaces of the valve` element 35. Whenthe valve 31 engages its seat under the conditions described,atmospheric pressure acting against the lower face of the valve it tendsto unseat it, but the area of this valve, being less than the total areaof the valve-49 and the surface of theelement 35 acted upon by airpressure, the valve 4i) will remain onits seat. The relative areas ofthe surfaces of the parts are `so designed, however, that the valve 46will move off its seat by further compressing the spring 3@ if theintake manifold vacuum increases substantially above the vacuum presentunder idling engine conditions. It is preferred that the valve il beunseated, after the valve 31 has engaged the seat 34, to again admit airinto the intake manifold at a manifold vacuum of at least 22 inches ofmercury. Under such conditions excessively high vacuums incident to veryhigh vehicle speeds and under light load conditions will result in theadmission of additional air into the intake manifold.

Thus it will be apparent that in the form of the invention illustratedin Figure 4 auxiliary air Will be admitted into the intake manifold atall manifold vacuums above approximately 10 inches of mercury except inthe range of Vacuum conditions which are present when the engine isidling, under which latter conditions it is highly desirable to cut offthe admission of air to prevent high idling speeds with the accompanyingnecessity for the frequent disengagement of the vehicle clutch whentraveling in slowtrafc.

It `will be apparent that the present device is particularly desirablefor use with heavy trucks and buses to assist in maintaining uniformvehicle speeds for given positions of the engine throttle. For a givenposition of the throttle the admission of auxiliary air will beincreased or will be completely cut off depending on variations in theload conditions on the engine. In this connection it is obvious thatintake manifold vacuums are dependent upon load conditions in proportionto the positio-ns of the throttle. When load conditions increase, thecutting off of the auxiliary air results in supplying normal fuelcharges to the engine to increase the power generated thereby to satisfyincreased power demands. When the power ydemands decrease, additionalair will be supplied to decrease the forces of the explosives of theengine, thus tending to retard vehicle speeds. It will be apparent thatas an incident to the operation of the present device, the dilution ofthe explosive mixture a substantial portion of the time during which avehicle is being operated results in material fuel savings.

It is well known that the use of a motor vehicle engine as means forretarding Vehicle speed when descending steep grades is highlydesirable, and this is particularly true in heavy trucks and buses.Ordinarily, a carburetor throttle is returned to idling position whendescending steep grades in which case the engine acts as a vacuum pumpto tend to retard vehicle speed. In the present construction, andparticularly the construction shown in Figure 4, the high vacuumconditions which will be present will permit the admission of air intothe engine to cause the latter to act in part as a compression pumptotend to retard vehicle speed. This is advantageous in that it materiallyreduces the heat otherwise generated in the cylinders of the engine andthe admission of cool air further tends to provide a cooling effect.

It will be apparent from the foregoing that the present constructionprovides two independent and balanced inlets, one for fuel and air, andthe other for auxiliary air, both acting in unison when conditions sorequire. A rich mixture is providedl when load conditions require thegeneration of additional power and when load conditions decrease and theengine speed increases, the kmodulating valve admits additional air tosubstantially reduce the richness of the fuel mixture according to theparticular conditions present. Thus the present device functions tosatisfy the volumetric demands of the engine and this is important fromthe standpoint of eflicient operation of the engine. Moreover, theadmission of additional air under high vacuum conditions reduces theextremely high vacuum conditions which otherwise would be present andprovides some elastic fluid against which the motor piston can act incompression, thus taking up mechanical slack in the parts and reducingythe noise of the motor, particularly in worn engines.

It is to be understood that the forms of the invention herewith'shownand described are to be taken as preferred examples of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of the subjoined claims.

I claim:

l. A control valve mechanism for an internal combustion engine having anintakemanifold', comprising a valve casing having an outlet and an inletfor communicating respectively with the intake manifold and theatmosphere,r a valve 'element in said casing biased in one directiontoward said inlet to a normal position and having a valve face operableinA said normal position for closing said inlet, said casing and saidvalve element having` cooperating faces constructed and arranged tometer the flow of air through said casing when said valve elementl ismoved away from said normal position whereby the rate of ow of airthrough said casing progressively increases as said valve element movesaway from said normal position, said valve element having an openingtherethrough, and an auxiliary valve normally closing said opening andvconstructed and arranged to be opened to permit the passage of air fromsaid inlet to said outlet when the pressure in the intake manifolddropsv to a point substantially below a predetermined point.

2. A control valve mechanism for an internal combustion engine having anintake manifold, comprising a valve casing having an outlet and an inletfor communicating respectively with the intake manifold and theatmosphere, a valve element in said 'casing biased in one directiontoward said inlet to a normal position and having a valve face operablein said normal position for closing said inlet, said casing and saidvalve element having cooperating faces constructedand arranged to meterVthe flow of air through said casing when said valve element is movedaway from said normal positionrwhereby the rate of flow of air throughsaid casing-progressively increases as sai-d valve element moves awayfrom said normal position, said valve element having a second valve faceconstructed and arrangedto close said outlet when the pressure in theintake manifold drops below a predetermined point, said valve elementhaving an opening therethrough, and an auxiliary valve normally closingsaid opening and constructed and arranged to be opened to permit thepassage of air from said inlet to said outlet when the pressure in theintake manifold drops toY a point substantially below said predeterminedpoint.

3. A control valve mechanism for an internal combustion engine having anintake manifold, comprising a valve casing having an outlet and an inletin its respective ends for communicating respectively with the intakemanifold and the atmosphere, the inner surface of said casing beingtapered to. decrease in size toward said inlet, and a valve element insaid casing having its outer face tapered to correspond with the taperof the inner surface of said valve casing and provided at one end with avalve face normally engageable with said casing to close said inlet, aspring biasing said valve element to said closed position,

the tapered faces of said valve and said casing substantially contactingWith each other in such closed position and serving to meter the passageof air through said casing when said valve element moves away from saidclosed position Y whereby the rate of flow of air through said casingprogressively increases as said valve eiement moves away from saidclosed position, the other end of said valve element having an end valveface engageable with said casing to close said i outlet when thepressure in the intake manifold drops below a predetermined point.

4. A control valve mechanism for an internal combustion engine having anintake manifold, comprising a valve casing having an outlet and an inletin its respective ends for communicating respectively with the intakemanifold and the atmosphere, the inner surface of said casing beingtapered to decrease in size toward said inlet, a valve element in saidcasing having its outer face tapered to correspond with the taper of theinner surface of said valve casing and provided at one end with a valveface normally engageable with said casing to close said inlet, a springbiasing said valve element to said closed position, the tapered faces ofsaid valve and said casing substantially contacting with each other insuch closed position and serving to meter the passage of air throughsaid casing when said valve element moves away from said closed posiltion whereby the rate of flow of air through said casing progressivelyincreases as said valve element moves away from said closed position,said valve element having an axial opening through the first named endthereof, and an auxiliary valve normally closing said axial opening andmovable to open position when the pressure in the intake manifold dropsto a point substantially lower than a predetermined point.

5. A control valve mechanism for an internal combustion engine having anintake manifold, comprising a valve casing having an outlet and an inletin its respective ends for communicating respectively with the intakemanifold-and the atmosphere, the inner surface of said casing beingtapered to decrease in size toward said inlet, a Valve element in saidcasing having its outer face tapered to correspond with the taper of theinner surface of said valve casing and provided at one end with a valveface normally engageable with saidcasing to close said'inlet,

fold drops below a predetermined point, said valve element beingprovided in the rst named end thereof with an axial opening, and aninwardly opening auxiliary valve engaged by said spring to be normallyheld in a position closing said axial opening, said auxiliary valvebeing movable to open position against the tension of said spring whenthe pressure in the intake manifold drops to a point substantially lowerthan 10 said predetermined point.

LEWIS JONES.

